A Study of the Stability and Characterization Plutonium Dioxide and Chemical Characterization [of] Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash

In the presentation ''A Study of the Stability and Characterization of Plutonium Dioxide'', the authors discuss their recent work on actinide stabilities and characterization, in particular, plutonium dioxide PuO{sub 2}. Earlier studies have indicated that PuO{sub 2} has the fluorite structure of CaF{sub 2} and typical oxide semiconductor properties. However, detailed results on the bulk electronic structure of this important actinide oxide have not been available. The authors have used all-electron, full potential linear combinations Gaussian type orbitals fitting function (LCGTO-FF) method to study PuO{sub 2}. The LCGTO-FF technique characterized by its use of three independent GTO basis sets to expand the orbitals, charge density, and exchange-correlation integral kernels. Results will be presented on zero pressure using both the Hedin-Lundquist local density approximation (LDA) model or the Perdew-Wang generalized gradient approximation (GGA) model. Possibilities of different characterizations of PuO{sub 2} will be explored. The paper ''Chemical Characterization Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash'' describes the results of a comprehensive study of the chemical characteristics of virgin, calcined and fluorinated incinerator ash produced at the Rocky Flats Plant and at the Los Alamos National Laboratory prior to 1988. The Rocky Flats and Los Alamos virgin, calcined, and fluorinated ashes were also dissolved using standard nitrate dissolution chemistry. Corresponding chemical evaluations were preformed on the resultant ash heel and the results compared with those of the virgin ash. Fluorination studies using FT spectroscopy as a diagnostic tool were also performed to evaluate the chemistry of phosphorus, sulfur, carbon, and silicon containing species in the ash. The distribution of plutonium and other chemical elements with the virgin ash, ash heel, fluorinated ash, and fluorinated ash heel particulates were studied in detail using microprobe analysis. Some of the more interesting results of these investigations are presented